The battery has become a primary power source for many portable electronic devices such as radios, hearing aids, watches, calculators and the like. In order to maintain the overall electronic devices as compact as possible, the electronic devices are usually designed with cavities to accommodate miniature batteries as their power source. The cavities are usually made so that a battery can be snugly positioned therein, thus making electronic contact with appropriate terminals within the device. To accommodate the electronic component manufacturers, the battery industry has adopted several conventional size button cells which the manufacturer can rely upon in designing their devices which require portable power sources. Due to the large number of battery-powered devices on the market, there has been a demand for increased power output capacities of standard size button cells. Accordingly, various anode-cathode couples have been employed so as to provide a sufficient output capacity to operate various devices. A problem has been encountered, however, when the density of the electrode bodies has to be increased in certain cell systems if maximum output power is to be achieved. Consequently, when increasing the density of the electrode bodies, two approaches can be taken; one of which is to maintain the same diameter and reduce the thickness and the other approach is to maintain the same thickness and reduce the diameter. If the diameter is unchanged and the thickness is reduced, an additional provision would have to be made to maintain the same gasket and opposing electrode height while, on the other hand, if the thickness is not changed but the diameter is decreased, a support is definitely needed for the cover. In addition, it was also noted that in certain cell systems it is necessary in order to obtain greater output capacity to add additional electrolyte into the cell. Although the densification of the electrode members would provide additional space for the electrolyte, it would have the disadvantage in that in order to properly seal the cell, it would be necessary to add a support member for the cover of the cell during the sealing operation.
Another major potential problem in certain types of battery power devices is that if the battery bulges, as could occur in miniature alkaline cells, the battery would usually become wedged within the cavity of the device which sometimes can result in damage to the device. One cause of cell bulging or other distortion of the cell's overall physical dimensions is due to the expansion of the cathode and/or formation of reaction products during cell discharge or during abusive discharge conditions.
It is, therefore, an important object of this invention to provide a compact cell structure that employs a gasket performing the dual function of providing the sealing means which is disposed and compressed between the cell's cover and the cell's container while also providing support means for the cover during the sealing operation while additionally providing longitudinal openings as reservoirs for an additional amount of the cell's electrolyte and/or openings which can accommodate any expansion of the cell's components or reaction products during discharge.
Another object of the present invention is to provide a dual sealing and cover support gasket for use in miniature type button cells.
Another object of the present invention is to provide a gasket for miniature type button cells having a first segment which is disposed and compressed between the rim of the cell's cover and the edge of the cell's container and a second segment extending within the container and substantially parallel to the wall of the cell's container and provided with a plurality of spaced-apart openings or cavities to accommodate additional electrolyte for the cell.
Another object of the present invention is to provide a gasket for miniature type button cells having a first segment which is disposed and composed between the rim of the cell's cover and the edge of the cell's container and a second segment extending within the container and substantially parallel to the wall of the cell's container and provided with a plurality of spaced-apart openings or cavities to accommodate any expansion of the cell's components or reaction products during discharge so as to effectively minimize cell distortion.
The following and additional objects will become more fully apparent from the following description and accompanying drawings.